A journalist before entering politics, Whittle has been the party’s culture spokesman for two years, and stood in Eltham in South East London during the general election.

In the past he has been a critic of multiculturalism, a potentially controversial view for a London mayor to hold given the diversity of the capital, a British city where white Britons do not constitute a majority.

“I think it is a priority now to look at how we best achieve integration, as opposed to the failed policy of multiculturalism which had been entrenched for years. Voices from both the left and right have admitted that a doctrinaire multicultural approach has led to social segregation, and a fragmenting of the kind of communal values which are crucial to the survival of any society.”

Whittle also topped the list of Greater London Authority candidates that Ukip is putting forward, with Evans placed third behind David Kurten, a chemistry teacher who stood for the seat of Camberwell and Peckham in May against Labour MP Harriet Harman.

Challenged by the BBC over whether Evans, who was interim leader during Nigel Farage’s temporary retirement after the general election, would have made a better candidate, Whittle said this was not the case.

In August party members briefed the press that the central committee used to select the London mayoral candidate was being harnessed to block Evans, a potential rival for Farage.

In the general election Ukip underperformed in London compared to the rest of the country, with the party picking up 8.1 percent of votes in the capital to put it at third place, below the 12.7 percent it scored nationally.